摘要
中点电压不平衡是三电平逆变器的固有问题。分析了不同电压矢量对中点电压的影响,研究了不同区间内,在调制波上叠加直流偏移量与中点电压间的关系,提出基于区间选择型的SVPWM三电平中点电压平衡控制策略。该方法仅需采样直流中点电压,通过选取合适的调整区间,在该区间内加入直流偏移量到调制波上,维持合成矢量作用顺序不变,改变合成矢量作用时间,通过重新分配大矢量、小矢量或零矢量作用时间,从而解决三电平逆变器中点电压不平衡的问题。实验结果验证了基于区间选择型的SVPWM三电平中点电压平衡控制策略的有效性。
The unbalance of the neutral point voltage is an inherent problem of NPC three-level inverter.The effect of neutral point voltage balancing which is caused by voltage vector is analyzed, and the relationship of the voltage offset and neutral point voltage in different regions is studied, a neutral point voltage balance strategy of three-level inverter based on region selection space vector pulse width modulation （SVPWM） is proposed, which only requires the information of the neutral point voltage.A voltage offset is added to the modulation wave in specific regions.The dwell times of synthesis vectors （large vectors, small vectors or zero vectors） are varied in order to solve the problem of the unbalance of the neutral point voltage, the sequence of the voltage vectors maintains unchanging.Experimental results show the neutral point voltage balancce control strategy based on region selection SVPWM is effective.
出处
《电力电子技术》
CSCD
北大核心
2012年第7期18-20,共3页
Power Electronics
关键词
逆变器
空间矢量
中点电压
区间选择
inverter
space vector
neutral point voltage
region selection
